传统法制备嗪草酮印迹聚合物

农药嗪草酮应用广泛,它的残留问题引起了人们的普遍关注,发展快速准确的检测方法势在必行。而分子印迹技术因其独特的优点使它成为痕量残留快速检测的一种较好的方法。采用传统法制备嗪草酮印迹聚合物,以甲基丙烯酸(MAA)为功能单体,N,N-亚甲基双丙烯酰胺为交联剂,甲苯为溶剂,在50℃时聚合得到选择性、吸附性最佳的印迹聚合物。     

Imprint characteristics of Pt/Pb(Zr,Ti)O3/Ir capacitors

The dynamic and static imprint characteristics of PZT thin film capacitors prepared by a two step reactive sputtering method were studied. The imprint is caused by an internal field generated by the trapping of electronic charges at interfacial layers that are injected, from the electrode. When unipolar pulse stressing is applied to the PZT capacitor, the cumulative time rather than the pulse cycles accounts more for the dynamic imprint characteristics. The amount of voltage shift in the polarization(P)-voltage(V) curve is reduced when the unipolar pulses are applied at elevated temperatures or a high amplitude pulse is applied. For static imprint stressing, the voltage shift increases with the temperature and is readily removed by application of bipolar pulses to the imprinted PZT capacitor at elevated temperatures. A method to estimate the lifetime limitation as a result of imprint failure in 1T/1C FRAMs is proposed.     

基于FFT图像差值在轮胎印痕识别中的研究

轮胎印痕识别对交通事故的现场勘测及事后侦查有着十分重要的作用.介绍了轮胎印痕识别在交通肇事逃逸案侦破中的具体应用,研究了基于FFT的图像差值原理,提出了基于FFT图像差值算法的轮胎印痕识别方法,并分析了具体的试验数据,结果显示,该方法有利于提高轮胎印痕识别的成功率,为快速查找肇事逃逸车辆提供了理论基础和科学依据.     

Surface Segregation Mechanisms in Ferroelectric Thin Films

Reliability issues have hampered the adoption of ferroelectric thin films by the microelectronics industry. One of these is imprint, an important problem affecting the performance of ferroelectric non-volatile memories. This paper presents the effects of the low temperature pyrolysis step on the chemical and physical properties of SrBi₂Ta₂O₉ films. A comparison of the hysteretic properties and composition profiles shows that control of the oxidising conditions during pyrolysis is critical to the dielectric properties. Data from this work and from the literature have been used to construct a model that explains the origin of surface depletion and segregation, self poling and as-grown imprint in ferroelectric films.     

印鉴识别相似度的计算框架

印鉴识别是计算机图像处理和模式识别技术的重要应用．基于模板匹配提出了一种印鉴识别相似度的算法框架，并应用于实际的印鉴识别过程．修正了经典相似度公式不能直接应用于实际的印鉴识别系统的问题，将差异像素点的特征信息加入到该算法中，使真假印鉴与预留印鉴匹配后的相似度结果很好地分布在阈值的两边．同时，为了使算法更加可靠和高效，引入多测度的相似度进行印鉴识别．实验结果表明，在不同层次的匹配级别上使用不同测度的相似度可以提高算法效率，而由多种相似测度综合而成的多测度相似度具有很强的区分性和鲁棒性．     

CHARACTERIZATION OF EFFECTIVE TIRE CONTACT AREA FOR VARIOUS TREAD PATTERNS

The effective tire-pavement contact area affects the relative damage of asphalt pavement and should be incorporated in both mechanistic and empirical response analyses of pavements. A new machine called ROTOCOM Wheel Tracker (RCWT) was designed and fabricated to capture the effective tire contact area apart from slab compacting, and conducting simulative laboratory wheel tracking tests. The main focus of this paper is laboratory measurement of effective tire contact areas for various tread patterns. Seven tire treads were selected for the footprint image analyses at five tire loads and four tire inflation pressures. An image processing MATLAB-based program was coded to calculate the contact areas of the 280 imprints obtained from both sides of the RCWT. Factorial analysis indicated significant effects of tire tread, tire load, and inflation pressure on the resulting contact area. Comparison between effective and traditional contact areas indicated that the current pavement design procedure with traditional circular contact area extremely overestimates the actual tire-pavement contact area up to 92%.     

Zn2+-imprinted porous polymer beads: Synthesis,structure, and selective adsorption behavior for template ion

Zn²⁺-imprinted polymer was synthesized in porous spherical forms via a self-assembled complex between 2,2′-bipyridyl/4-vinylpyridine complexant/functional monomer and Zn²⁺ template ion. Diameters of particles ranged from 250 to 550 μm to enlarge the surface area and thus enhance the adsorption capacity. The presence/absence of the template ion in the preparation of the imprinted polymer was confirmed by EDX spectroscopy, and the physical structure of the particles was investigated using ESEM and BET analysis. The particle and the pore size were controlled by the cross-linker/monomer feed ratio. The adsorption capacity of the imprinted polymers was 210.61 μmol g^?1 for Zn²⁺, while those for Cu²⁺, Ni²⁺, and Pb²⁺, were 37.92 μmol g^?1, 33.02 μmol g^?1, and 9.70 μmol g^?1, respectively. This big discrepancy of the adsorption capacities illustrates the excellent separation selectivity of the imprinted polymers. The adsorption capacity decreased significantly at pH below 4.5, as the polymers are easily protonated. The imprinted particles lost only 10 % of their adsorption ability after 10 repeated uses.     

Cell Signal Distribution and Imprint Reliability in FeRAM with Hybrid Bit Line Architecture

We have investigated the cell signal distributions of ferroelectric random access memories (FeRAMs) using newly developed design scheme, hybrid bit line architecture and their reliability against imprint degradation. Since FeRAMs have relatively large signal distributions due to nonuniform ferroelectric storage capacitors, cell signal interference between neighboring bit lines severely degrades the sensing signal margin. In order to remove the cross-talk noise, hybrid bit line architecture is developed, which is a combination of the conventional folded and open bit line schemes. The lifetime against imprint degradation of FeRAM devices is also increased using hybrid bit line architecture.